Most modern refrigeration equipment employs one of several organic solvent compositions, such as chlorofluorocarbon compounds (CFCs), as a working fluid (refrigerant).
For various reasons, such as wearing of the seals in the refrigeration equipment's compressor, the refrigerants in the equipment may eventually become contaminated with dirt, oil and/or moisture. These contaminants affect the efficiency of the equipment and may eventually lead to damage of the compressor and other components in the equipment. Thus, it is typically required that the refrigerant in the equipment be replaced at intervals to avoid damage to the equipment and to restore the equipment's overall efficiency. Also, in the event of a failure of the equipment, it is typically required that the refrigerant be removed from the equipment prior to servicing.
Previously, the most common method of removing the refrigerant from the equipment was to vent the refrigerant into the atmosphere and to replace it with virgin refrigerant as required. However, problems exist with this method of removing the refrigerant.
The release of CFC compounds into the atmosphere results in the depletion of the ozone layer therein. As the ozone layer is the principal filter in the atmosphere for removing the sun's ultraviolet radiation, much concern has been expressed about its depletion as it is expected to lead to many problems. For example, it is expected that an upturn in related health problems such as skin cancer will occur. Accordingly, many governments are passing legislation restricting or prohibiting the use of and/or release of CFC compounds into the atmosphere. These restrictions pose a serious problem to refrigeration equipment manufacturers and servicers who no longer can release CFC-type refrigerants into the atmosphere.
A second problem in regard of venting of refrigerants to the atmosphere exists, albeit one with a lesser impact, is the fact that the virgin refrigerant compounds required for replacement of vented refrigerants are expensive and, in the case of CFCs, may be difficult to obtain.